The Restoration of the Cutty Sark by Grimshaw

Grimshaw’s new London berth for Britain’s last tea clipper mixes engineering prowess with nautical preservation.

Tool Box: Raising the Cutty Sark

Hoisting the fragile 650-ton vessel to its new resting place 3 meters (9.8 feet) above ground was a frightening prospect. Even after inserting 150 tons of strengthening steelwork into the ship, structural engineers could not be sure how the Cutty Sark would respond. Over the years, corrosion had affected some parts of the hull more than others: There was a real risk that she might twist and fracture during the operation.

“The moment of truth is when it lifts off the ground,” said Wolf Mangelsdorf of Buro Happold in a BBC interview shortly before the lift. “That’s the point when you know if you have got it right or wrong. There is nothing you can do.”

But the challenge could not be ducked. At sea, the ship’s weight was supported uniformly by the water. But resting on her keel in a dry dock for more than 50 years, she had sagged under the stress of her own weight. Already the hull was warped. If left in place, the ship could have eventually collapsed into matchwood.

Any fears proved misplaced. In May 2011, the Cutty Sark, supported by 24 hydraulic jacks each capable of lifting 200 tons, began its slow ascent; her progress was tracked by cameras inside the hull and an array of sophisticated monitors, which fed data to the engineers. The entire lift took two days to complete, before the Cutty Sark was at last anchored in position by 24 giant steel struts extending diagonally from the walls of the dry berth. Her last voyage was over.

When the architects at the British firm Grimshaw won the contract to restore the Cutty Sark, they were taking on a national treasure. The last and greatest of the tea clippers, the ship, now berthed in London, is a matchless monument to the Age of Sail. Launched in 1869, she was then among the fastest sailing ships afloat, designed to carry tea from China at a time when speed to market was crucial. And not only was she quick, she was elegant and innovative, too. With the sleek lines of a modern racing yacht, her wooden hull, measuring 84 by 11 meters (275 by 36 feet), concealed ribs of iron. “I have worked on some big projects in the past, but this one was unique,” says Diane Metcalfe, an associate director at Grimshaw, who helped to oversee the project until its completion this year.

The ship, a masterpiece of 19th-century construction, was showing her age by the 1990s. Since 1954, she had sat in a dry dock next to the Thames in Greenwich, open to the public. Planks were rotting, corrosion had destroyed much of the iron frame, and the ship was slowly bulging out of shape. Restoration was vital, but meeting the brief of the vessel’s owners, the Cutty Sark Trust, was no easy task. Space at the site was tight, yet the trust wanted better access and more facilities for retail and exhibition space. Compounding the problem was the ship’s acutely sensitive location, right next to Sir Christopher Wren’s Old Royal Naval College at the heart of a World Heritage Site.

Grimshaw’s solution was bold. A new steel-and-glass-diagrid canopy envelopes the Cutty Sark, meeting the hull of the ship at what was once the waterline, and continuing down to encompass a new entrance and retail spaces. To relieve stress on the ship’s structure and to redistribute the load, the team worked closely with engineers from Buro Happold, and devised a system of supports: The vessel now rests on 12 triangular steel frames—formed from horizontal beams and diagonal ties—shaped like inverted coat hangers, inserted through the hull. These frames carry the weight of the Cutty Sark’s keel and mast back up to new external support points.

A new access tower beside the ship (which also contains elevators and restroom facilities) directs the flow of visitors from the main entrance through the lower cargo deck at the ship’s stern up onto the main deck. From there, visitors proceed to the concrete dry-berth, a space under the ship left over as the result of raising and suspending the Cutty Sark 3 meters (9.8 feet) off the ground (see “Tool Box: Raising the Cutty Sark”). This move provides 1,000 square meters (10,764 square feet) beneath the ship on the dry dock’s floor for use as a café, exhibition space, and corporate entertaining.

Work began in 2004, but a fire three years later set the restoration back several months. (Thank­fully, the damage was limited). When Queen Elizabeth II finally reopened the Cutty Sark to the public this April, the restoration results were spectacular. For the first time, visitors can walk beneath—and touch—the ship’s hull, reclad in dazzling Muntz metal, a gold-colored alloy of copper and zinc. “It’s a cathedral-like space,” Metcalfe says. “It still gives me goose bumps just to go down there.”

Inevitably, the £50 million ($81.2 million) reimagining of the landmark has resulted in divided opinion. Some say the glass canopy obscures the view of the hull, and that raising the ship above ground has robbed it of its nautical character; the interior is less controversial, and many say it is a fitting tribute to a national treasure. Love it or hate it, the project ensures the survival of a relic from England’s great naval history for at least another 50 years, when it may be time to revisit the Cutty Sark again.